# Now Thats What we call a Summation!

Algebra Level 4

$\large \sum^\infty_{r=1} \frac{r^3+(r^2+1)^2}{(r^4+r^2+1)(r^2+r)} = \frac ab$

The equation above holds true for coprime positive integers $a$ and $b$. Find $a+b$.

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